The uranium enricher Urenco has completed a UK trial where it produced a new type of nuclear fuel called LEU+, which is designed to be used by existing UK gigawatt-scale and planned small modular reactors (SMRs), and can last longer than traditional LEU (low enriched uranium).
Analysis and results from the trial were confirmed on 1 May and the production trial took five days to complete, from 26 April to 30 April.
A Urenco spokesperson told NCE: “As a result of this trial, this was the first commercial production of LEU+ in the UK and Europe. That said, the quantity produced is only for the purposes of the trial run.”
LEU+ represents an advancement from LEU, which is widely used in gigawatt-scale reactors.
Mining involves extracting uranium ore from the ground and crushing it into uranium oxide powder called “yellowcake”.
Conversion involves a chemical process where the yellowcake is turned into uranium hexafluoride, or “hex”.
Enrichment involves heating the hex, which turns it into a gas, and then spinning it in centrifuges at extremely high speeds. This separates Uranium-235 from Uranium-238.
U-235 can split under nuclear fission, and the goal of enrichment for LEU is to achieve 3-5% of U-235. From 3-5% of enriched U-235 can sustain a chain reaction in most existing deployed reactor designs. LEU+ is enriched to 5 to 10%.
The final stage is fabrication, where enriched uranium gas is turned into a powder for pressing into ceramic pellets, which are stacked into fuel rods and assemblies. Those assemblies are then loaded into nuclear reactors.
The UK does have natural uranium deposits but they are not economically viable, so it is entirely reliant on imports. Australia has the largest reserves – 28% of global reserves. While Russia has 8%.
Other reserves are located in Kazakhstan (14%), Canada (10%), Namibia (8%), South Africa (5%), Niger (6%), China (5%) and Brazil (3%).
Urenco is the UK’s leading enricher. It does not ship its finished product to nuclear power stations, because its product must be fabricated by specialist fabrication providers.
This means that once prospective LEU+ customers give Urenco the go-ahead to start supplying them, Urenco would transport its LEU+ to fabricators, and then the fabricated fuel would be sent on to nuclear power stations.
In a press release from the company, Urenco head of advanced fuels (commercial) Magnus Mori, said: “Urenco is committed to enriching uranium for the reactors of today and tomorrow.
“This production trial of LEU+ at Capenhurst has provided a successful outcome and demonstrates our commitment to advancing the nuclear industry in the UK and globally.
“We are continuing to focus on implementing other operational measures for LEU+, including transport solutions, as a next step.”
NCE spoke with Urenco chief operating officer Bridget Sparrow ahead of the announcement (on 6 May), where she explained the benefits of LEU+ compared to LEU.
Sparrow said that the LEU+ is for light water reactors (LWRs). LWR reactor technology is at the heart of pressurised water reactors (PWR) – such as Sizewell B. In addition, Rolls-Royce SMR’s reactor design is based on standard PWR technology.
Sizewell C (main image above) and Hinkley Point C both use European pressurised water reactor (EPR) technology and could both potentially choose to use LEU+. Contracts for purchases of LEU+ may not be publicly disclosed and Urenco does not generally disclose information about its clients.
The benefit of LEU+, according to Sparrow, “is that using LEU+ allows [reactors] to run for longer, because typically a reactor has to go into what’s called a turnaround or a shutdown to replace the fuel.”
She added that LEU+ is “more efficient from a cost per unit perspective”.
“Different reactors have different durations between turnarounds. But let’s say, if one was currently doing a turnaround every 18 months, [using LEU+ instead of LEU] it would extend it to two years,” Sparrow said, and added that LEU+ provides an “incremental improvement” compared to LEU.
“We haven’t had the demand from the industry before” for LEU+, Sparrow said.
“Most of the interest for LEU+ initially is in the US. We have some interest in Europe, but, it’s very early days. That’s what I would say in terms of determining exactly where the market is going to be.”
Aside from finalising commercial contracts with end users, such as nuclear power plant owners, the remaining hurdle for Urenco to be able to bring its newly established LEU+ production capability to market is a suitable container for the uranium.
“We’re working with a company called Orano to provide us with a container that’s suitable for transporting LEU+,” she said.
“They’re almost ready to provide us with that. And as soon as we have it, then we can start to transport it in the UK and Europe. We do have a transport solution for our facility in the US, but that is not available to us in Europe.”
A Urenco spokesperson clarified to NCE that, although the LEU+ trial has finished, the company is “finalising the safety arrangements and processes with the UK regulator.
“So that’s all there is left to do with it,” they said
“And one part of that is the transportation.”
While Urenco is drawing attention to its LEU+ production capabilities, its plans to produce high-assay low-enriched uranium (HALEU) require much more investment.
The UK Government has made HALEU a big focus of its nuclear policy, including by investing up to £300M to establish a UK HALEU supply chain.
“HALEU is a much larger investment for us because we have to build a new plant to produce HALEU [whereas] we can use our existing facilities to produce LEU+,” Sparrow said.
She added that Urenco may in future decide to use its LEU+ as a feedstock for producing HALEU, but that would be subject to customer demands.
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